Speaker
Description
By choosing a suitable set of cosmological parameters, one can classify them into two groups with respect to their impact on the linear matter power spectrum $P_\mathrm{L}(k)$ when it is expressed in Mpc units: the evolution parameters, $\Theta_\mathrm{e}$, which determine its amplitude at a given redshift and the shape parameters, $\Theta_\mathrm{s}$, which only affect its shape. This division results in a perfect degeneracy in the impact of the evolution parameters on the $P_\mathrm{L}(k)$ which can, in turn, be accounted for by a single parameter: $\sigma_{12}$, the rms linear density variance on spheres of a radius of 12 Mpc.
Sanchez et al. 2021 has shown that this degeneracy is present also on the non-linear power spectrum where it presents differences between cosmologies with various evolution parameters that can be predicted by looking at their different structure formation histories. We show how this “evolution mapping” framework can be extended also to describe the non-linear velocity field, which is a crucial ingredient to model the impact of redshift-space distortions on clustering statistics.
